The present invention generally relates to a layout display apparatus for displaying a print image (layout) and, more particularly, is directed to a layout display apparatus for a tape printing apparatus capable of forming a label on which an inputted sentence having one line or more is printed out.
A tape printing apparatus prints out an inputted character (conceptionally containing a symbol) string having one line or more on a continuous tape, if required, and also cuts the printed tape to be ejected therefrom. This inputted character string will be referred to as a "sentence". Recently, such a tape printing apparatus capable of printing out not only the sentence having 1 line, but also the sentence having two lines or more on a cut tape (hereinafter referred to as a "label") has been proposed, taking account of such a fact that the label may be utilized in various fields.
Also in such a tape printing apparatus, like other information processing apparatuses having printing functions such as wordprocessors, a layout display apparatus for displaying a printed image is mounted. Therefore, users may confirm the arrangement or the like of the printing content of the label to be formed by way of the layout display without printing out the inputted sentence on the expensive tape, while operating the layout display apparatus.
On the other hand, the tape printing apparatuses are made compact and lower in cost, as compared with other information processing apparatuses, and moreover may merely display an entire portion or a part of a sentence having several lines. Accordingly, the display regions of the display units (for example, liquid crystal displays) provided for the tape printing apparatuses are typically small. Since the dot number of the printing head would give influences to printing qualities, the total dot number thereof should be selected to be a sufficient value capable of maintaining the required printing qualities. However, actually, the total dot number of such a display unit is set to a limited number because of the requirement for its compactness and low cost. For instance, even when the total dot number of the printing head is selected to be 62 dots or 96 dots, the size of the display area of the display unit is selected to be almost 16 dots (in a main scanning direction).times.48 dots (in a sub-scanning direction), or 16 dots.times.96 dots. As to the tape functioning as the printing medium, the length of this tape along the width direction (the main scanning direction) is fixed, whereas the length thereof along the longitudinal direction (the sub-scanning direction) is not fixed but may be cut at a proper length, depending upon the length of the inputted sentence, which is completely different from the printing media employed in other apparatuses.
Since the tape printing apparatus owns such a specific feature, as compared with other information processing apparatuses, the layout display unit mounted on this tape printing apparatus is different from that mounted on other information processing apparatuses.
The conventional layout display apparatus mounted on the tape printing apparatus will now be described briefly.
When a selection key for a layout display function is manipulated under such a condition that the inputted sentence is displayed on the display unit, the operation thereof is entered into a layout display mode. Then, a user will confirm the width of the tape loaded on the tape printing apparatus at this time, and further will recognize various attributes such as the character sizes of the inputted sentence for each line, and the printing styles (right-justification printing, constant-length printing or the like), so that the input sentence is expanded into a dot expansion buffer with employment of the font information stored in a character generator ROM (CG-ROM). This sentence expansion is similar to the expansion used for the printing. The dot pattern expanded in this manner is converted at the reduction rate determined by the size of the display area of the display apparatus, and thereafter, the reduction-converted dot pattern is stored into the display buffer. For example, the dot pattern is reduction-converted in order that the dot number of the display apparatus along the main scanning direction corresponds to the tape width. In the display apparatus, after the head portion of the pattern information stored in the display buffer is displayed, the entire pattern information is displayed in the scrolling manner along the left direction. When the layout content at the end position along the longitudinal direction of the printing tape is displayed, the scrolling display is accomplished. Thus, the layout display is performed.
The capacities of the dot expansion buffer and the display buffer are not so large, and both the dot expanding operation and the pattern reduction conversion or the like may be repeated in conjunction with the layout display during the layout display operation period.
As described above, in the conventional layout display apparatus, the dot pattern is converted at the reduction rate in accordance with such a fact that the total dot number of the display apparatus along the main scanning direction is smaller than the total dot number of the printing head. Further, this layout display apparatus employs the scrolling display in correspondence with such a fact that the lengths of the printed labels along the sub-scanning direction are different from each other for each of the inputted sentences.